258 PETROLEUM TECHNOLOGY, ECONOMICS, AND POLITICS
to sizes less than about one millimeter, an energy intensive task that
would result in an expensive disposal problem. Such fine particles
might be used in a lower temperature process for sequestering
carbon dioxide (Fenton, 1977).
Disposal of spent shale is also a problem that must be solved
in economic fashion for the large-scale development of oil shale to
proceed.
Retorted shale contains carbon as char, representing more than
half of the original carbon values in the shale. The char is potentially pyrophoric and can burn if dumped into the open air while
hot. The heating process results in a solid that occupies more volume than the fresh shale because of the problems of packing random particles. A shale oil industry producing 100,000 barrels per
day — about the minimum for a world-scale operation — would
process more than 100,000 tons of shale and result in an amount
of spent shale that is equivalent to a block more than 100 feet on a
side, assuming some effort at packing to conserve volume. Part of
the spent shale could be returned to the mined-out areas for remediation, and some can potentially be used as feed for cement kilns.
In situ processes avoid the spent shale disposal problems because
the spent shale remains where it is created but, on the other hand,
the spent shale will contain uncollected liquids that can leach into
ground water, and vapors produced during retorting can potentially escape to the aquifer (Karanikas et al., 2005).
As the demand for light hydrocarbon fractions constantly
increases, there is much interest in developing economical methods
for recovering liquid hydrocarbons from oil shale on a commercial scale. However, the recovered hydrocarbons from oil shale are
not yet economically competitive against the petroleum crude produced. Furthermore, the value of hydrocarbons recovered from oil
shale is diminished because of the presence of undesirable contaminants. The major contaminants are sulfurous, nitrogenous, metallic,
and organometallic compounds, which cause detrimental effects
to various catalysts used in the subsequent refining processes.
These contaminants are also undesirable because of their disagreeable odor, corrosive characteristics, and combustion products that
further cause environmental problems.
Oil shale still has a future and remains a viable option for the production of liquid fuels. Many of the companies involved in earlier
oil shale projects still hold their oil shale technology and resource
assets. The body of knowledge and understanding established by
to sizes less than about one millimeter, an energy intensive task that
would result in an expensive disposal problem. Such fine particles
might be used in a lower temperature process for sequestering
carbon dioxide (Fenton, 1977).
Disposal of spent shale is also a problem that must be solved
in economic fashion for the large-scale development of oil shale to
proceed.
Retorted shale contains carbon as char, representing more than
half of the original carbon values in the shale. The char is potentially pyrophoric and can burn if dumped into the open air while
hot. The heating process results in a solid that occupies more volume than the fresh shale because of the problems of packing random particles. A shale oil industry producing 100,000 barrels per
day — about the minimum for a world-scale operation — would
process more than 100,000 tons of shale and result in an amount
of spent shale that is equivalent to a block more than 100 feet on a
side, assuming some effort at packing to conserve volume. Part of
the spent shale could be returned to the mined-out areas for remediation, and some can potentially be used as feed for cement kilns.
In situ processes avoid the spent shale disposal problems because
the spent shale remains where it is created but, on the other hand,
the spent shale will contain uncollected liquids that can leach into
ground water, and vapors produced during retorting can potentially escape to the aquifer (Karanikas et al., 2005).
As the demand for light hydrocarbon fractions constantly
increases, there is much interest in developing economical methods
for recovering liquid hydrocarbons from oil shale on a commercial scale. However, the recovered hydrocarbons from oil shale are
not yet economically competitive against the petroleum crude produced. Furthermore, the value of hydrocarbons recovered from oil
shale is diminished because of the presence of undesirable contaminants. The major contaminants are sulfurous, nitrogenous, metallic,
and organometallic compounds, which cause detrimental effects
to various catalysts used in the subsequent refining processes.
These contaminants are also undesirable because of their disagreeable odor, corrosive characteristics, and combustion products that
further cause environmental problems.
Oil shale still has a future and remains a viable option for the production of liquid fuels. Many of the companies involved in earlier
oil shale projects still hold their oil shale technology and resource
assets. The body of knowledge and understanding established by